Thought-controlled 'smart' prosthetic studied

Two million people in the United States need a prosthetic limb. For many, it can mean mobility and more independence. There's a new generation of prosthetics that are like nothing anyone has ever seen before, including a thought-controlled "smart" limb.

He builds, lifts and climbs: Not much slows down Zac Vawter. Not even an amputated leg.

"I lost my leg in a motorcycle accident," said Vawter.

Vawter uses a prosthetic limb. It helps him get around, but it has its limitations.

"If I walked up and left the knee locked and sat down, it stays locked," said Vawter.

But a new thought-controlled Myoelectric leg does what Vawter's prosthetic can't. Before he could use it, orthopedic surgeon Doug Smith took nerves from his lower leg and redirected them to his hamstring muscle.

"Instead of firing when you think about bending your knee, it would fire when you think about raising your ankle," said Smith.

When Vawter wants to move the leg, the brain signal travels down his spinal cord through the nerves. Electrodes in the prosthetic pick up signals from the muscles.

"And you can have a prosthetic device that actually works according to your thoughts," said Smith.

The device is still being studied, so Vawter can't use it at home. But he looks forward to the day he can.

"Stairs with that leg, with the bionic leg, is really phenomenal," said Vawter.

Until now, only thought-controlled arms were available. Although the cost of the bionic leg hasn't been determined, researchers say a version could be available for consumer use within three to five years.